U.S. patent application number 13/446951 was filed with the patent office on 2013-04-25 for rechargeable battery.
The applicant listed for this patent is Sang-Won Byun, Soo-Seok Choi, Min-Yeol Han, Jeong-Won Oh, Hae-Kwon Yoon. Invention is credited to Sang-Won Byun, Soo-Seok Choi, Min-Yeol Han, Jeong-Won Oh, Hae-Kwon Yoon.
Application Number | 20130101870 13/446951 |
Document ID | / |
Family ID | 46168329 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130101870 |
Kind Code |
A1 |
Byun; Sang-Won ; et
al. |
April 25, 2013 |
RECHARGEABLE BATTERY
Abstract
A rechargeable battery including an electrode assembly including
a first electrode, a second electrode, and a separator between the
first and second electrodes; a case housing the electrode assembly;
a cap plate covering an opening of the case; an electrode terminal
extending through the cap plate; a lead tab including a fuse part
and connecting the electrode terminal and the electrode assembly;
and an auxiliary discharge path between opposite sides of the fuse
part and having a second electrical resistance value greater than a
first electrical resistance value of the fuse part.
Inventors: |
Byun; Sang-Won; (Yongin-si,
KR) ; Choi; Soo-Seok; (Yongin-si, KR) ; Oh;
Jeong-Won; (Yongin-si, KR) ; Han; Min-Yeol;
(Yongin-si, KR) ; Yoon; Hae-Kwon; (Yongin-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Byun; Sang-Won
Choi; Soo-Seok
Oh; Jeong-Won
Han; Min-Yeol
Yoon; Hae-Kwon |
Yongin-si
Yongin-si
Yongin-si
Yongin-si
Yongin-si |
|
KR
KR
KR
KR
KR |
|
|
Family ID: |
46168329 |
Appl. No.: |
13/446951 |
Filed: |
April 13, 2012 |
Current U.S.
Class: |
429/7 |
Current CPC
Class: |
Y02E 60/10 20130101;
H01M 2/26 20130101; H01M 10/0431 20130101; H01M 2200/103 20130101;
H01M 2/348 20130101; H01M 4/661 20130101; H01M 4/665 20130101; H01M
2/263 20130101; H01M 4/70 20130101; H01M 10/443 20130101; H01H
79/00 20130101 |
Class at
Publication: |
429/7 |
International
Class: |
H01M 2/02 20060101
H01M002/02; H01M 2/30 20060101 H01M002/30; H01M 2/00 20060101
H01M002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 25, 2011 |
KR |
10-2011-0109357 |
Claims
1. A rechargeable battery comprising: an electrode assembly
comprising a first electrode, a second electrode, and a separator
between the first and second electrodes; a case housing the
electrode assembly; a cap plate covering an opening of the case; an
electrode terminal extending through the cap plate; a lead tab
including a fuse part and connecting the electrode terminal and the
electrode assembly; and an auxiliary discharge path between
opposite sides of the fuse part and having a second electrical
resistance value greater than a first electrical resistance value
of the fuse part.
2. The rechargeable battery of claim 1, wherein the auxiliary
discharge path is configured to electrically insulate between the
opposite sides of the fuse part when the rechargeable battery is in
a normal state and electrically conduct between the opposite sides
of the fuse part when the rechargeable battery is in a
short-circuited state.
3. The rechargeable battery of claim 1, wherein the lead tab
includes a first connection part connected to the electrode
terminal, and a second connection part connected to the electrode
assembly, and wherein the fuse part is at the first connection
part.
4. The rechargeable battery of claim 1, wherein the auxiliary
discharge path is formed by an insert injection part formed by
insert-injecting the fuse part of the lead tab.
5. The rechargeable battery of claim 4, wherein the auxiliary
discharge path is further formed by an insulation member insulating
the insert injection part and the lead tab from an inner surface of
the cap plate.
6. The rechargeable battery of claim 5, wherein at least one of the
insert injection part and the insulation member is formed of
polypropylene (PP) of 70 to 90 wt % and carbon of 10 to 30 wt
%.
7. The rechargeable battery of claim 5, wherein at least one of the
insert injection part and the insulation member is formed of
polyphenylenesulfide (PPS) of 70 to 90 wt % and carbon of 10 to 30
wt %.
8. The rechargeable battery of claim 1, wherein the auxiliary
discharge path is formed by an insulation member insulating the
lead tab from an inner surface of the cap plate.
9. The rechargeable battery of claim 1, wherein the auxiliary
discharge path is formed of a material having an electrical
resistivity of 10 to 1*10.sup.6 ohm*cm.
10. The rechargeable battery of claim 1, wherein the auxiliary
discharge path is formed by a connection member connecting the
opposite sides of the fuse part of the lead tab.
11. The rechargeable battery of claim 10, wherein the lead tab is
made of aluminum or copper, and the connection member is made of
stainless steel.
12. The rechargeable battery of claim 1, wherein the electrode
terminal comprises a negative terminal installed in an insulation
structure at the cap plate, and a positive terminal installed in an
electric-conduction structure at the cap plate, and wherein the
fuse part is formed at the lead tab connected to the positive
terminal.
13. The rechargeable battery of claim 12, wherein the auxiliary
discharge path connects the opposite sides of the fuse part to the
positive terminal.
14. The rechargeable battery of claim 1, wherein the rechargeable
battery is adapted for use as a motor-driving power source for
propelling an electric vehicle or a hybrid electric vehicle.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2011-0109357, filed on Oct. 25,
2011 in the Korean Intellectual Property Office, the entire content
of which is incorporated herein by reference,
BACKGROUND
[0002] 1. Field
[0003] Aspects of embodiments of the present invention elate o a
rechargeable battery.
[0004] 2. Description of the Related Art
[0005] A rechargeable battery can repetitively perform charge and
discharge, unlike a primary battery. A small-capacity rechargeable
battery is commonly used with a portable compact electronic device,
such as a mobile phone, a laptop computer, or a camcorder, and a
large-capacity rechargeable battery is widely used as a
motor-driving power supply, such as for driving a motor of a hybrid
vehicle or an electric vehicle,
[0006] Recently, a high-power rechargeable battery using a
non-aqueous electrolyte having a high energy density has been
developed. The high-power rechargeable battery is configured by
connecting a plurality of rechargeable batteries in series and may
be used for devices requiring a large amount of power, such as a
motor drive of an electric vehicle and the like.
[0007] The rechargeable battery includes an electrode assembly
including a positive electrode and a negative electrode at both
sides of a separator, a case housing the electrode assembly, a cap
plate sealing an opening of the case, and electrode terminals
installed through the cap plate to be electrically connected to the
electrode assembly.
[0008] Since charging and discharging are repeated in the
rechargeable battery, excessive heat may be generated from the
inside of the case, or an electrolyte solution may be decomposed.
The heat generation or decomposition of the electrolyte solution
may cause the internal pressure of the rechargeable battery to be
increased. The increase in internal pressure may cause the
rechargeable battery to ignite or explode.
[0009] In order to prevent fire and/or explosion caused by the
increase in internal pressure, an external short-circuit part may
be provided outside the case. The external short-circuit part short
circuits the negative electrode and the positive electrode of the
electrode assembly with each other outside the rechargeable battery
when the internal pressure of the rechargeable battery increases.
When the external short-circuit part performs a short circuit
operation, a charging state of the electrode assembly is decreased
due to discharge of a large current. A weak part of a discharge
line connecting the electrode assembly and the electrode terminal
may be melted and broken due to the discharge of the large
current.
[0010] In order to effectively disconnect the discharge line in an
external short circuit or overcharge, a fuse part may be provided
at a lead tab connecting the electrode terminal and the electrode
assembly in the rechargeable battery. However, the fuse part is
melted and broken and thereafter, when a broken portion is small,
an arc may be generated at the broken portion.
[0011] An arc generated in the rechargeable battery may act on the
electrolyte solution to cause fire or explosion, thereby
deteriorating stability of the rechargeable battery.
[0012] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
described technology and therefore it may contain information that
does not form the prior art that is already known in this country
to a person of ordinary skill in the art.
SUMMARY
[0013] According to an aspect of embodiments of the present
invention, a rechargeable battery is configured to prevent or
substantially prevent arc generation in a fuse part after the fuse
part is disconnected.
[0014] According to an exemplary embodiment of the present
invention, a rechargeable battery includes: an electrode assembly
including a first electrode, a second electrode, and a separator
between the first and second electrodes; a case housing the
electrode assembly; a cap plate covering an opening of the case; an
electrode terminal extending through the cap plate; a lead tab
including a fuse part and connecting the electrode terminal and the
electrode assembly; and an auxiliary discharge path between
opposite sides of the fuse part and having a second electrical
resistance value greater than a first electrical resistance value
of the fuse part.
[0015] The auxiliary discharge path may be configured to
electrically insulate between the opposite sides of the fuse part
when the rechargeable battery is in a normal state and electrically
conduct between the opposite sides of the fuse part when the
rechargeable battery is in a short-circuited state.
[0016] The lead tab may include a first connection part connected
to the electrode terminal and a second connection part connected to
the electrode assembly, and the fuse part may be at the first
connection part.
[0017] The auxiliary discharge path may be formed by an insert
injection part formed by insert-injecting the fuse part of the lead
tab.
[0018] The auxiliary discharge path may be further formed by an
insulation member insulating the insert injection part and the lead
tab from an inner surface of the cap plate.
[0019] At least one of the insert injection part and the insulation
member may be formed of polypropylene (PP) of 70 to 90 wt % and
carbon of 10 to 30 wt %.
[0020] At least one of the insert injection part and the insulation
member may be formed of polyphenylenesulfide (PPS) of 70 to 90 wt %
and carbon of 10 to 30 wt %.
[0021] The auxiliary discharge path may be formed by an insulation
member insulating the lead tab from an inner surface of the cap
plate.
[0022] The auxiliary discharge path may be formed of a material
having an electrical resistivity of 10 to 1*10.sup.6 ohm*cm.
[0023] The auxiliary discharge path may be formed by a connection
member connecting the opposite sides of the fuse part of the lead
tab.
[0024] The lead tab may be made of aluminum or copper, and the
connection member may be made of stainless steel.
[0025] The electrode terminal may include a negative terminal
installed in an insulation structure at the cap plate and a
positive terminal installed in an electric-conduction structure at
the cap plate, and the fuse part may be formed at the lead tab
connected to the positive terminal.
[0026] The auxiliary discharge path may connect the opposite sides
of the fuse part to the positive terminal.
[0027] The rechargeable battery may be adapted for use as a
motor-driving power source for propelling an electric vehicle or a
hybrid electric vehicle.
[0028] According to an aspect of embodiments of the present
invention, a discharging path is formed through a fuse part by a
high electrical resistance value of an auxiliary discharge path in
a normal operation state by connecting opposite sides of the fuse
part provided at a lead tab to the auxiliary discharge path, and a
high-voltage current is discharged to the auxiliary discharge path
after the fuse part is broken by an external short circuit, such
that an arc is prevented or substantially prevented from occurring
in the fuse part. As such, a rechargeable battery according to
embodiments of the present invention is particularly suited for
application in an electric vehicle or a hybrid electric
vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, together with the specification,
illustrate some exemplary embodiments of the present invention,
and, together with the description, serve to explain aspects and
principles of the present invention.
[0030] FIG. 1 is a perspective view of a rechargeable battery
according to an exemplary embodiment of the present invention.
[0031] FIG. 2 is a cross-sectional view of the rechargeable battery
of FIG. 1, taken along the line II-II.
[0032] FIG. 3 is a partial exploded perspective view of the
rechargeable battery of FIG. 1.
[0033] FIG. 4 is a cross-sectional view of a lead tab and an
insulation member of the rechargeable battery of FIG. 1, taken
along the line IV-IV of FIG. 3.
[0034] FIG. 5 is a cross-sectional view of a lead tab and an
insulation member of a rechargeable battery according to another
exemplary embodiment of the present invention.
[0035] FIG. 6 is a perspective view showing a lead tab of a
rechargeable battery according to another exemplary embodiment of
the present invention.
TABLE-US-00001 Description of Reference Numerals Indicating Some
Elements in the Drawings 10: Electrode assembly 11: First electrode
(negative electrode) 11a, 12a: Coated region 11b, 12b: Uncoated
region 12: Second electrode 13: Separator (positive electrode) 15:
Case 20: Cap plate 21: First terminal 21a, 22a: Rivet terminal
(negative terminal) 21b, 22b: Flange 21c, 22c: Plate terminal 22:
Second terminal 23: Short-circuit hole (positive terminal) 24: Vent
hole 25: Vent plate 25a: Notch 27: Sealing cap 29: Electrolyte
injection opening 31, 32: First and second electrode lead tab 36,
37: First and second gasket 38: Insulation member 41, 42: First and
second 50: External short-circuit insulation member part 51:
Short-circuit tab 53: Short-circuit member 60: Fuse part 61: Insert
injection part 62: Connection member 311, 312: Terminal hole 321,
322: First and second P1: Discharge path connection part P2, P3,
P4: Auxiliary W, W1, W2: Width discharge path
DETAILED DESCRIPTION
[0036] The present invention will be described more fully
hereinafter with reference to the accompanying drawings, in which
some exemplary embodiments of the invention are shown and
described. However, as those skilled in the art would realize, the
described embodiments may be modified in various different ways,
all without departing from the spirit or scope of the present
invention. Accordingly, the drawings and description are to be
regarded as illustrative in nature and not restrictive. Like
reference numerals designate like elements throughout the
specification.
[0037] FIG. 1 is a perspective view of a rechargeable battery
according to an exemplary embodiment of the present invention, and
FIG. 2 is a cross-sectional view of the rechargeable battery of
FIG. 1, taken along the line II-II. Referring to FIGS. 1 and 2, the
rechargeable battery according to an exemplary embodiment of the
present invention includes an electrode assembly 10 to charge and
discharge a current, a case 15 housing the electrode assembly 10, a
cap plate 20 covering an opening of the case 15, a first terminal
21 (e.g., a negative electrode terminal) and a second terminal 22
(e.g., a positive electrode terminal) which are installed at the
cap plate 20, an external short-circuit part 50 provided at the
first terminal 21 side, and a fuse part 60 (see FIG, 3) provided at
the second terminal 22 side.
[0038] In one embodiment, in the electrode assembly 10, a first
electrode 11 (e.g., a negative electrode) and a second electrode 12
(e.g., a positive electrode) are disposed at both sides of a
separator 13 as an insulator, and the first electrode 11, the
separator 13, and the second electrode 12 are wound in a jelly roll
shape,
[0039] Further, the electrode assembly 10 may be assembled by
laminating the negative electrode and the positive electrode which
are formed as a single plate with the separator interposed
therebetween or by folding and laminating the negative electrode,
the separator, and the positive electrode in a zigzag manner (not
shown).
[0040] The first electrode 11 and the second electrode 12 include
coated regions 11a and 12a formed by coating active materials on a
current collector of a metal plate, and uncoated regions 11b and
12b formed by an exposed current collector on which the active
materials are not coated,
[0041] In one embodiment, the uncoated region 11b of the first
electrode 11 is formed at one end of the first electrode 11 along
the wound first electrode 11, and the uncoated region 12b of the
second electrode 12 is formed at one end of the second electrode 12
along the wound second electrode 12, such that the uncoated regions
11b and 12b are disposed at both ends of the electrode assembly 10,
respectively.
[0042] In one embodiment, the case 15 is formed having a
substantially cuboid shape and has an inner space housing the
electrode assembly 10 and an electrolyte solution therein and has
an opening connecting the outside with the inner space which is
formed on one surface of the cuboid. The opening allows the
electrode assembly 10 to be inserted into the inner space of the
case 15,
[0043] The cap plate 20, in one embodiment, is formed of a thin
metal (e.g., steel) plate and installed at the opening of the case
15 to seal the case 15. The cap plate 20, in one embodiment,
includes an electrolyte injection opening 29 and a vent hole
24.
[0044] The electrolyte injection opening 29 allows an electrolyte
to be injected into the case 15 after connecting the cap plate 20
to the case 15. After injecting the electrolyte, the electrolyte
injection opening 29 is sealed with a sealing cap 27.
[0045] The vent hole 24 is sealed with a vent plate 25 to discharge
an internal pressure of the rechargeable battery. When the internal
pressure of the rechargeable battery reaches a certain pressure
(e.g., a predetermined pressure), the vent plate 25 is broken or
ruptured to open the vent hole 24. The vent plate 25, in one
embodiment, has a notch 25a to induce the breaking or
rupturing.
[0046] The first terminal 21 and the second terminal 22, in one
embodiment, are installed by passing through the cap plate 20 and
are electrically connected to the electrode assembly 10. In one
embodiment, the first terminal 21 (e.g., a negative terminal) is
electrically connected to the first electrode 11 (e.g., a negative
electrode) of the electrode assembly 10, and the second terminal 22
(e.g., a positive electrode) is electrically connected to the
second electrode 12 (e.g., a positive electrode) of the electrode
assembly 10. Accordingly, the electrode assembly 10 is drawn out to
the outside of the case 15 through the first terminal 21 and the
second terminal 22.
[0047] In one embodiment, the first terminal 21 and the second
terminal 22 have the same structure as each other at the inside of
the cap plate 20, and the same structure is therefore described
together herein, and outside of the cap plate 20, the first
terminal 21 and the second terminal 22 have different structures
from each other, and the different structures will be separately
described.
[0048] In one embodiment, the first and second terminals 21 and 22
include rivet terminals 21a and 22a installed at terminal holes 311
and 312 of the cap plate 20, respectively, flanges 21b and 22b
widely formed and integral with the rivet terminals 21a and 22a at
the inside of the cap plate 20, and plate terminals 21c and 22c
disposed at the outside of the cap plate 20 to be connected to the
rivet terminals 21a and 22a, such as by riveting or welding.
[0049] First and second gaskets 36 and 37 are installed between the
rivet terminals 21a and 22a of the first and second terminals 21
and 22 and the inner surfaces of the terminal holes 311 and 312 of
the cap plate 20, respectively, to seal between the rivet terminals
21a and 22a of the first and second terminals 21 and 22 and the cap
plate 20. The first and second gaskets 36 and 37, in one
embodiment, further extend between the flanges 21b and 22b and the
inner surface of the cap plate 20 to further seal between the
flanges 21b and 22b and the cap plate 20. That is, the first and
second gaskets 36 and 37 are installed between the first and second
terminals 21 and 22 and the cap plate 20, thereby preventing or
substantially preventing the electrolyte solution from leaking
through the terminal holes 311 and 312.
[0050] In one embodiment, the rechargeable battery includes a
plurality of electrode assemblies 10 (see FIG. 3). In the electrode
assemblies 10, the first electrodes 11 are electrically connected
to each other by a first electrode lead tab 31 (e.g., a negative
electrode lead tab) and the second electrodes 12 are electrically
connected to each other by a second electrode lead tab 32 (e.g., a
positive electrode lead tab). Although not shown, the present
invention may also be applied to a rechargeable battery having one
electrode assembly.
[0051] The first and second electrode lead tabs 31 and 32
electrically connect the first and second terminals 21 and 22 to
the first and second electrodes 11 and 12 of the electrode assembly
10, respectively. In one embodiment, the first and second electrode
lead tabs 31 and 32 are connected to lower ends of the rivet
terminals 21a and 22a to caulk the lower ends, such that the first
and second electrode lead tabs 31 and 32 are supported by the
flanges 21b and 22b and connected to the lower ends of the rivet
terminals 21a and 22a.
[0052] First and second insulation members 41 and 42 are installed
between the first and second electrode lead tabs 31 and 32,
respectively, and the cap plate 20 to electrically insulate the
first and second electrode lead tabs 31 and 32 and the cap plate
20. In one embodiment, one side of each of the first and second
insulation members 41 and 42 is connected to the cap plate 20 and
the other side thereof surrounds the respective first or second
electrode lead tab 31 or 32, the rivet terminal 21a or 22a, and the
flange 21b or 22b, thereby stabilizing the connection structure
thereof.
[0053] An external short-circuit part 50 is described below with
reference to the plate terminal 21c. Referring to FIG. 2, the
external short-circuit part 50 includes a short-circuit tab 51 and
a short-circuit member 53 which are either separated from each
other or short circuited, depending on an internal pressure in the
case 15.
[0054] In one embodiment, the short-circuit tab 51 is electrically
connected to the rivet terminal 21a of the first terminal 21 (e.g.,
the negative terminal) and disposed at the outside of the cap plate
20 with an insulation member 38 interposed therebetween. The
insulation member 38 is installed between the short-circuit tab 51
and the cap plate 20 to electrically insulate the short-circuit tab
51 and the cap plate 20 from each other. That is, the cap plate 20
is electrically insulated from the first terminal 21.
[0055] In one embodiment, the short-circuit tab 51 and the terminal
plate 21c are connected to an upper end of the rivet terminal 21a
to caulk the upper end, such that the short-circuit tab 51 and the
terminal plate 21c are connected to the upper end of the rivet
terminal 21a. Accordingly, the short-circuit tab 51 and the
terminal plate 21c are fixedly supported to the cap plate 20 with
the insulation member 38 interposed therebetween.
[0056] The short-circuit member 53 is installed in a short-circuit
hole 23 of the cap plate 20. The short-circuit tab 51 is connected
to the first terminal 21 and extends toward the short-circuit
member 53. The short-circuit tab 51 and the short-circuit member 53
face each other in the short-circuit hole 23 in either a separated
state (depicted by solid line in FIG. 2) or a short-circuited state
(depicted by dashed line in FIG. 2).
[0057] When the internal pressure of the rechargeable battery
increases (e.g., exceeds a predetermined pressure), the
short-circuit member 53 is modified from the separated state to the
short-circuited state to be contacted to the short-circuit tab 51.
In the short-circuited state, the short-circuit tab 51 and the cap
plate 20 are electrically connected to each other to maintain the
short-circuited state of the electrode assembly 10. In the short
circuit, a high-voltage current is rapidly (e.g., instantaneously)
discharged between the first and second terminals 21 and 22 through
the short-circuit tab 51 and the short-circuit member 53. Also, in
the short circuit, a fuse part 60 may be melted and broken, or cut,
in a discharge line connecting the electrode assembly 10 and the
first and second terminals 21 and 22.
[0058] FIG. 3 is a partial exploded perspective view of the
rechargeable battery of FIG. 1, showing the second lead tab 32 and
the second insulation member 42, and FIG. 4 is a cross-sectional
view of the second lead tab 32 and the second insulation member 42,
taken along the line IV-IV of FIG. 3. In one embodiment, FIGS. 3
and 4 show the second lead tab 32 that may be a positive electrode
lead tab and the second insulation member 42 that may be a positive
insulation member,
[0059] Referring to FIGS. 2 to 4, the fuse part 60 is provided at
the second terminal 22 (e.g., the positive terminal) side. The fuse
part 60 is provided at the second electrode lead tab 32 so as to be
melted and broken by discharging the high-voltage current due to
the operation of the external short-circuit part 50.
[0060] The second electrode lead tab 32, in one embodiment,
includes a first connection part 321 connected to the second
terminal 22 and a second connection part 322 curved at an end of
the first connection part 321 to be connected to the electrode
assembly 10. In one embodiment, the fuse part 60 is formed at the
first connection part 321 in a structure of increased electrical
resistance with widths W1 and W2 smaller than a width W of the
first connection part 321 and at both sides of the first connection
part 321 in a widthwise direction (i.e. the y-axis direction shown
in FIG. 3).
[0061] The fuse part 60, in one embodiment, is formed at both sides
of the first connection part 321 in the widthwise direction,
thereby decreasing a reduction of mechanical strength of the first
and second connection parts 321 and 322 due to the formation of the
fuse part 60.
[0062] The fuse part 60 forms a discharge path (P1) when the
rechargeable battery is normally driven, and the rechargeable
battery according to an exemplary embodiment of the present
invention further forms an auxiliary discharge path (P2)
discharging the high-voltage current when the fuse part 60 is
melted and broken by the external short circuit.
[0063] In one embodiment, the auxiliary discharge path (P2) forms
an insulation structure when the rechargeable battery is normally
driven and forms an electric-conduction structure when the fuse
part 60 is melted and broken. The fuse part 60 has a low first
electrical resistance value, and the auxiliary discharge path (P2)
has a second electrical resistance value greater than the first
electrical resistance value.
[0064] According to one exemplary embodiment, the auxiliary
discharge path (P2) is formed by an insert injection part 61 formed
by insert-injecting the fuse part 60 of the second electrode lead
tab 32. When the fuse part 60 is in a normal state, the current is
blocked by high electrical resistance of the insert injection part
61, and the normal current is discharged through the fuse part 60
(P1).
[0065] However, when the fuse part 60 is melted and broken, then
the high-voltage current flows, in spite of the high electrical
resistance of the insert injection part 61, and the high-voltage
current is discharged through the insert injection part 61 along
the auxiliary discharge path (P2). Accordingly, an arc does not
occur in the broken, or cut, portion of the fuse part 60. As such,
a rechargeable battery according to embodiments of the present
invention is particularly suited for application in an electric
vehicle or a hybrid electric vehicle.
[0066] In one embodiment, auxiliary discharge paths (P2) and (P3)
may be formed by the insert injection part 61 formed by
insert-injecting the fuse part 60 of the second electrode lead tab
32 and the second insulation member 42 insulation-supporting the
first connection part 321 of the second electrode lead tab 32. When
the fuse part 60 is in a normal state, the current is blocked by
high electrical resistance of the insert injection part 61 and the
second insulation member 42, and the normal current is discharged
through the fuse part 60 along the discharge path (P1).
[0067] However, when the fuse part 60 is melted and broken, then
the high-voltage current flows, in spite of the high electrical
resistance of the insert injection part 61 and the second
insulation member 42, and the high-voltage current is discharged
through the insert injection part 61 and the second insulation
member 42 along auxiliary discharge paths (P2) and (P3).
Accordingly, an arc does not occur in the broken, or cut, portion
of the fuse part 60. A difference in the high-voltage current
amounts flowing into the auxiliary discharge paths (P2) and (P3)
may occur according to the electrical resistance values of the
insert injection part 61 and the second insulation member 42, and,
in one embodiment, the insert injection part 61 and the second
insulation member 42 may have the same electrical resistance
value.
[0068] In one embodiment, for example, the insert injection part
61, or both the insert injection part 61 and the second insulation
member 42, may be formed of polypropylene (PP) of 70 to 90 wt % and
carbon of 10 to 30 wt %, or may be formed of polyphenylenesulfide
(PPS) of 70 to 90 wt % and carbon of 10 to 30 wt %.
[0069] Polypropylene and polyphenylenesulfide provide an insulation
property to the insert injection part 61 and the second insulation
member 42 to increase an electrical resistance value according to
an increase in the content thereof, and carbon provides an
electric-conduction property to the insert injection part 61 and
the second insulation member 42 to decrease the electrical
resistance value according to an increase in the content
thereof.
[0070] In one embodiment, the insert injection part 61 and the
second insulation member 42 have an electrical resistivity of 10 to
1*10.sup.6 ohm*cm, such that the insert injection part 61 and the
second insulation member 42 having the second electrical resistance
value function as an insulation member for the discharge current
when the rechargeable battery is normally driven and function as a
conductive member for the high-voltage discharge current.
[0071] When the electrical resistivity is less than 10 ohm*cm, the
insert injection part or the second insulation member malfunctions
as a conductive member for the normal current according to a change
in a use environment when the rechargeable battery is normally
driven, thereby externally short circuiting the rechargeable
battery.
[0072] Further, when the electrical resistivity is greater than
1*10.sup.6ohm*cm, the insert injection part or the second
insulation member malfunctions as an insulation member even for the
high-voltage current when the rechargeable battery is externally
short circuited, such that the high-voltage current may not be
discharged.
[0073] Various other exemplary embodiments of the present invention
are described below, in which repeated description of components,
features, and configurations which are the same as shown and
described above with respect to the above-described exemplary
embodiment is omitted. In the exemplary embodiment shown and
described above, the auxiliary discharge path (P2) is formed by the
insert injection part 61, and the auxiliary discharge path (P3) is
formed by the second insulation member 42.
[0074] FIG. 5 is a cross-sectional view of a lead tab and an
insulation member of a rechargeable battery according to another
exemplary embodiment of the present invention. Referring to FIG. 5,
the auxiliary discharge path (P3) is formed by the second
insulation member 42 housing and supporting the fuse part 60 of the
second lead tab 32, but the insert injection part 61 and the
auxiliary discharge path (P2) formed thereby are not present. When
the fuse part 60 is in a normal state, the current is blocked by
high electrical resistance of the second insulation member 42 and
the normal current is discharged through the fuse part 60 along the
discharge path (P1).
[0075] However, when the fuse part 60 is melted and broken, then
the high-voltage current flows, in spite of the high electrical
resistance of the second insulation member 42, and the high-voltage
current is discharged through the second insulation member 42 along
the auxiliary discharge path (P3). Accordingly, an arc does not
occur in the broken, or cut, portion of the fuse part 60.
[0076] FIG. 6 is a perspective view showing a lead tab of a
rechargeable battery according to another exemplary embodiment of
the present invention. Referring to FIG. 6, an auxiliary discharge
path (P4) has a second electrical resistance value and is formed by
a connection member 62 connecting both sides (i.e. opposite sides)
of the fuse part 60 of a lead tab 32' (e.g., a positive electrode
lead tab). One end of the connection member 62 may be connected
(e.g., welded or caulked) and curved at a lower surface of the
first connection part 321 and the other end of the connection
member 62 may be connected (e.g., welded or caulked) at a side
surface of the second connection part 322.
[0077] In one embodiment, the lead tab 32' may be made of a
material, such as aluminum or copper, having relatively low
electrical resistance, and the connection member 62 may be made of
a material, such as stainless steel, having relatively high
electrical resistance. When the fuse part 60 is in a normal state,
the current is blocked by the high electrical resistance of the
connection member 62, and the normal current is discharged through
the fuse part 60 along the discharge path (P1).
[0078] However, when the fuse part 60 is melted and broken, then
the high-voltage current flows, in spite of the high electrical
resistance of the connection member 62, and the high-voltage
current is discharged through the connection member 62 along the
auxiliary discharge path (P4). Accordingly, an arc does not occur
in the broken, or cut, portion of the fuse part 60.
[0079] While the present invention has been described in connection
with certain exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims, and equivalents thereof.
* * * * *